Muffler temperature single vs dual ?

Roy Ale

Member
Oct 20, 2020
55
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Victoria BC
Exhaust system question in Lounge as car is not an Oldsmobile . Car has an in line 6 with a single exhaust . Issue might be design of car , its a Fox body unibody . I am having an issue with heat transfer from the muffler to the inside floor of the car . The muffler has a heat shield built into the top of it , and at least an inch of air space between muffler and under side of car . Will stay with a single out from exhaust manifold , then maybe splitting off the exhaust Y to two mufflers. Would adding one more muffler / dual reduce down the temperature of the mufflers ? Or would they both be the same as what the single was . Has anyone gone from single to double and noticed the muffler temps drop ?
 

Olds 307 and 403

Well-known member
Oct 4, 2018
882
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Melville, Saskatchewan
I did on my 88 Olds, can't say I did notice temp but it did help flow. How large is the muffler? It could be partially plugged. If a mouse nest is inside blocking it, that could be the issue.
 

Roy Ale

Member
Thread starter
Oct 20, 2020
55
11
8
Victoria BC
I would think more flow should be less heat . So adding one more pipe and one more muffler would reduce heat from the one muffler . is that thinking on the right track ? if yes ! then we may go with duals on the inline 6 .

The muffler is big for a Fox body car , and yes could be other issues with muffler on the car. maybe should have shop remove muffler for a look see inside . its not the original muffler , my wife would have asked for a quiet muffler . I think quiet means more restrictions which means more heat .

Could be a Fox body design fault as well . the factory attached a fibreglass mat to the under side of the back seat , just above the muffler , so the factory knew this was going to be an issue. I put a temperature gauge under the fibreglass mat , just a short drive around town the gauge was 152 o/ F
 

Olds 307 and 403

Well-known member
Oct 4, 2018
882
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Melville, Saskatchewan
The Dynomax Superturbo flow decent and are quite. True duals are always best.
 

Roy Ale

Member
Thread starter
Oct 20, 2020
55
11
8
Victoria BC
Link is about the dynomax super turbo muffler . OP is a fox body car with a 6cyl engine / one barrel carb / so not looking for performance on this car . But others might be . And may put these on my 307 . The thread is interesting / inside diameter of tubes and pics of muffler cut open . says the D S T is a 1960 s chevy Corvair turbo muffler. thread.html
 
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Olds 307 and 403

Well-known member
Oct 4, 2018
882
263
63
Melville, Saskatchewan
Yeah, the Dynomax is a compromise on noise control for maximum flow. Of course you can put on the classic Flowmaster 40 and get neither.
 

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